Knife sharpener



FIG. 1 is a perspective view of the knife sharpener;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a right elevation view thereof;

FIG. 5 is a left elevation view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is a perspective view showing the knife sharpener in a second position of use, wherein a sharpening rod is in an extended position of use;

FIG. 9 is a perspective view of the knife sharpener in a third position of use, wherein a foot is deployed;

FIG. 10 is a front elevation view thereof;

FIG. 11 is a rear elevation view thereof;

FIG. 12 is a right elevation view thereof;

FIG. 13 is a left elevation view thereof;

FIG. 14 is a top plan view thereof; and,

FIG. 15 is a bottom plan view thereof.

The broken lines depict portions of the knife sharpener in which the design is embodied that are not considered part of the claimed design. 

CLAIM The ornamental design for a knife sharpener, as shown and described. 